Cpp: use references for non-trivial types in accessors

The generated accessors used by-value return and parameter types even for non-trivial types. This change is intended to improve the situation by introducing usage of reference for the mentioned non-trivial types. This change: - introduces usage of const references for non-trivial types in getters defined via accessors attribute for structures when it is called on l-value - introduces usage of by-value type for non-trivial types in getters defined via accessors attribute for structures when it is called on r-value - introduces usage of const references for non-trivial types in setters - strips constness and references from type used to select a hash in 'StructHashImpl.mustache' because std::hash<T> does not accept references/constness for T - updates output of smoke tests to show, that since this commit the generated accessors use const references for non-trivial types Signed-off-by: Patryk Wrobel <[email protected]>
heremaps · Oct 25, 2024 · f914c76 · f914c76
1 parent 51a9c4b
commit f914c76
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## Unreleased
 ### Bug fixes:
+ * C++: Fixed generation of getters and setters for accessors attribute -- non-trivial types use references now.
  * Added missing generation of conversion functions for lambdas defined in structs for Swift.
 
 ## 13.9.5

diff --git a/gluecodium/src/main/resources/templates/cpp/CppStruct.mustache b/gluecodium/src/main/resources/templates/cpp/CppStruct.mustache
@@ -1,6 +1,6 @@
 {{!!
   !
-  ! Copyright (C) 2016-2020 HERE Europe B.V.
+  ! Copyright (C) 2016-2024 HERE Europe B.V.
   !
   ! Licensed under the Apache License, Version 2.0 (the "License");
   ! you may not use this file except in compliance with the License.
@@ -51,10 +51,17 @@ public:
 }}{{#if attributes.cpp.accessors}}
 {{#set structElement=this}}{{#fields}}
 {{prefixPartial "cpp/CppFieldDoc" "    "}}
-    {{resolveName typeRef}} {{resolveName this "" "getter"}}( ) const { return {{resolveName}}; }{{!!
+    {{#ifPredicate typeRef "needsRefSuffix"}}const {{resolveName typeRef}}&{{!!
+}} {{resolveName this "" "getter"}}( ) const & { return {{resolveName}}; }
+    {{resolveName typeRef}} {{resolveName this "" "getter"}}( ) const && { return {{resolveName}}; }{{/ifPredicate}}{{!!
+}}{{#unlessPredicate typeRef "needsRefSuffix"}}{{resolveName typeRef}}{{!!
+}} {{resolveName this "" "getter"}}( ) const { return {{resolveName}}; }{{/unlessPredicate}}{{!!
 }}{{#unless structElement.attributes.immutable}}
 {{prefixPartial "cpp/CppFieldDoc" "    "}}
-    void {{resolveName this "" "setter"}}( {{resolveName typeRef}} value_ ) { {{resolveName}} = value_; }{{!!
+    void {{resolveName this "" "setter"}}( {{!!
+}}{{#ifPredicate typeRef "needsRefSuffix"}}const {{resolveName typeRef}}&{{/ifPredicate}}{{!!
+}}{{#unlessPredicate typeRef "needsRefSuffix"}}{{resolveName typeRef}}{{/unlessPredicate}}{{!!
+}} value_ ) { {{resolveName}} = value_; }{{!!
 }}{{/unless}}
 {{/fields}}{{/set}}
 

diff --git a/gluecodium/src/main/resources/templates/cpp/StructHashImpl.mustache b/gluecodium/src/main/resources/templates/cpp/StructHashImpl.mustache
@@ -1,6 +1,6 @@
 {{!!
   !
-  ! Copyright (C) 2016-2020 HERE Europe B.V.
+  ! Copyright (C) 2016-2024 HERE Europe B.V.
   !
   ! Licensed under the Apache License, Version 2.0 (the "License");
   ! you may not use this file except in compliance with the License.
@@ -23,8 +23,8 @@ hash< {{resolveName "FQN"}} >::operator( )( const {{resolveName "FQN"}}& t ) con
 {
     size_t hash_value = 43;
 {{#if attributes.cpp.accessors}}
-    {{#resolveName "FQN"}}{{#set structName=this}}{{#fields}}hash_value = (hash_value ^ {{>common/InternalNamespace}}hash< decltype({{!!
-    }}std::declval<{{structName}}>().{{resolveName this "" "getter"}}()) >()(t.{{resolveName this "" "getter"}}())) << 1;
+    {{#resolveName "FQN"}}{{#set structName=this}}{{#fields}}hash_value = (hash_value ^ {{>common/InternalNamespace}}hash< std::remove_cv_t< std::remove_reference_t< decltype({{!!
+    }}std::declval<{{structName}}>().{{resolveName this "" "getter"}}()) > > >()(t.{{resolveName this "" "getter"}}())) << 1;
     {{/fields}}{{/set}}{{/resolveName}}
 {{/if}}{{#unless attributes.cpp.accessors}}
 {{#fields}}

diff --git a/.../src/test/resources/smoke/equatable/output/cpp/src/smoke/EquatableStructWithAccessors.cpp b/.../src/test/resources/smoke/equatable/output/cpp/src/smoke/EquatableStructWithAccessors.cpp
@@ -1,33 +1,43 @@
 // -------------------------------------------------------------------------------------------------
 //
+
 //
 // -------------------------------------------------------------------------------------------------
+
 #include "smoke/EquatableStructWithAccessors.h"
 #include <utility>
+
 namespace smoke {
+
 EquatableStructWithAccessors::EquatableStructWithAccessors( )
     : foo_field{ }
 {
 }
+
 EquatableStructWithAccessors::EquatableStructWithAccessors( ::std::string foo_field )
     : foo_field( std::move( foo_field ) )
 {
 }
+
 bool EquatableStructWithAccessors::operator==( const EquatableStructWithAccessors& rhs ) const
 {
     return foo_field == rhs.foo_field;
 }
+
 bool EquatableStructWithAccessors::operator!=( const EquatableStructWithAccessors& rhs ) const
 {
     return !( *this == rhs );
 }
+
+
 }
+
 namespace gluecodium {
 std::size_t
 hash< ::smoke::EquatableStructWithAccessors >::operator( )( const ::smoke::EquatableStructWithAccessors& t ) const
 {
     size_t hash_value = 43;
-    hash_value = (hash_value ^ ::gluecodium::hash< decltype(std::declval<::smoke::EquatableStructWithAccessors>().get_foo_field()) >()(t.get_foo_field())) << 1;
+    hash_value = (hash_value ^ ::gluecodium::hash< std::remove_cv_t< std::remove_reference_t< decltype(std::declval<::smoke::EquatableStructWithAccessors>().get_foo_field()) > > >()(t.get_foo_field())) << 1;
     return hash_value;
 }
 }
diff --git a/gluecodium/src/test/resources/smoke/structs/output/cpp/include/smoke/Structs.h b/gluecodium/src/test/resources/smoke/structs/output/cpp/include/smoke/Structs.h
@@ -112,11 +112,14 @@ class _GLUECODIUM_CPP_EXPORT Structs {
 
         double get_trivial_double_field( ) const { return trivial_double_field; }
 
-        ::std::string get_nontrivial_string_field( ) const { return nontrivial_string_field; }
+        const ::std::string& get_nontrivial_string_field( ) const & { return nontrivial_string_field; }
+        ::std::string get_nontrivial_string_field( ) const && { return nontrivial_string_field; }
 
-        ::smoke::Structs::Point get_nontrivial_point_field( ) const { return nontrivial_point_field; }
+        const ::smoke::Structs::Point& get_nontrivial_point_field( ) const & { return nontrivial_point_field; }
+        ::smoke::Structs::Point get_nontrivial_point_field( ) const && { return nontrivial_point_field; }
 
-        std::optional< ::smoke::Structs::Point > get_nontrivial_optional_point( ) const { return nontrivial_optional_point; }
+        const std::optional< ::smoke::Structs::Point >& get_nontrivial_optional_point( ) const & { return nontrivial_optional_point; }
+        std::optional< ::smoke::Structs::Point > get_nontrivial_optional_point( ) const && { return nontrivial_optional_point; }
 
     };
 
@@ -142,17 +145,20 @@ class _GLUECODIUM_CPP_EXPORT Structs {
 
         void set_trivial_double_field( double value_ ) { trivial_double_field = value_; }
 
-        ::std::string get_nontrivial_string_field( ) const { return nontrivial_string_field; }
+        const ::std::string& get_nontrivial_string_field( ) const & { return nontrivial_string_field; }
+        ::std::string get_nontrivial_string_field( ) const && { return nontrivial_string_field; }
 
-        void set_nontrivial_string_field( ::std::string value_ ) { nontrivial_string_field = value_; }
+        void set_nontrivial_string_field( const ::std::string& value_ ) { nontrivial_string_field = value_; }
 
-        ::smoke::Structs::Point get_nontrivial_point_field( ) const { return nontrivial_point_field; }
+        const ::smoke::Structs::Point& get_nontrivial_point_field( ) const & { return nontrivial_point_field; }
+        ::smoke::Structs::Point get_nontrivial_point_field( ) const && { return nontrivial_point_field; }
 
-        void set_nontrivial_point_field( ::smoke::Structs::Point value_ ) { nontrivial_point_field = value_; }
+        void set_nontrivial_point_field( const ::smoke::Structs::Point& value_ ) { nontrivial_point_field = value_; }
 
-        std::optional< ::smoke::Structs::Point > get_nontrivial_optional_point( ) const { return nontrivial_optional_point; }
+        const std::optional< ::smoke::Structs::Point >& get_nontrivial_optional_point( ) const & { return nontrivial_optional_point; }
+        std::optional< ::smoke::Structs::Point > get_nontrivial_optional_point( ) const && { return nontrivial_optional_point; }
 
-        void set_nontrivial_optional_point( std::optional< ::smoke::Structs::Point > value_ ) { nontrivial_optional_point = value_; }
+        void set_nontrivial_optional_point( const std::optional< ::smoke::Structs::Point >& value_ ) { nontrivial_optional_point = value_; }
 
     };